Monohalotriazine dyes are well known to be generally useful for dyeing cellulosic fibers. However, these dyes have a drawback in that a considerable amount of the dye used is not fixed on the fiber because a side reaction occurs between the halotriazine reactive group and water instead of the reaction between the halotriazine reactive group and cellulose, thereby resulting in a low color value and poor build-up property of the dyed fiber. Besides such a loss of dye, the pollution on dyeing waste water containing the unfixed dye causes social problems such as environmental pollution.
It is also known that bis(monohalotriazine) dyes having an enforced affinity for cellulosic fibers are obtained by reacting two moles of a dihalotriazine with one mole of a diamine for the purpose of improving the fixing ratio of dye. This type of dye, however, generally exhibits a reverse relationship between the solubility of dye in water and the affinity of dye for cellulosic fibers, that is to say, the dye having the higher water-solubility tends to exhibit the lower affinity for cellulose fibers.
Consequently, the dye circles have been looking for a dye having a sufficient solubility in water as well as a strong affinity for cellulose fibers and high fixing ratio.